Stinger missile
=Stinger missile= From PyroGuide The name stinger missile seems to have become fairly common among pyro hobbyists to refer to the class of rockets which are spin stabilized. This means that the usual efforts to assure a predictable flight path of a rocket, which include body fins or a guide stick, can all be dispensed with. Consequently, the spin stabilized rocket is extremely easy to make. This is what makes them so much fun. Unlike a girandola project, these little jewels can be made in a few minutes and launched immediately. It's a great fix for the smoke addicted pyro who often needs to throw something together quickly. The methods presented here closely follow those first described by Warren Klofkorn some 10 years ago. His article appears in "The Best of AFN II" on page 62 and has become the standard reference for stinger missile construction. A description of my personal experience with his instructions and a few other innovations, hints and tips are included here in the hope that they might make your experience more enjoyable. Somewhere between 6 cc and 9 cc of this composition, damped with a sparing amount of alcohol, is pressed into the top of the tube using moderate pressure only. It is a good idea to give this delay composition a little drying time before adding the final heading to the rocket. The diagram at the left shows the internal structure of the missiles after a heading of flash powder has been added. There is nothing sacred about this particular way of making a delay. Dextrin can be substituted for the rice starch or a totally different delay composition can be used. I am a little partial to some of the glitter formulas, myself, such as Winokur #39. |- | valign="top"|http://www.pyroguide.com/index.php?title=Image:Stinge06.jpg http://www.pyroguide.com/index.php?title=Image:Stinge06.jpgClick for larger imageNow we are ready to talk about the various heading options for our stingers. After all, what's the point of making a rocket that just spins as it flies if it doesn't do something cool at the end of its flight? The easiest heading is 3 cc of flash powder in the remaining cavity of the stinger tube. This is finished by gluing (white or Elmer's glue) a 3/4 inch end plug that just touches the flash powder enough to keep it from shifting during the spinning ascent. An easy shell header with stars an be constructed using a 1-1/2 inch length of paper tube whose inside dimension is 1-1/4 inches. This tube is glued to the stinger tube with a 1/2 inch overlap. The expanded cavity now has more room to accommodate a larger payload of stars and burst. The payload space needs to be filled completely and firmly packed so that no asymmetries can be created when the stinger spins. The cavity can be closed in a variety of ways. A typical end plug or cap will do the trick, but if you want to maximize your payload space, a molded nose cone can be used. The nose cone shown in the picture is molded from craft paper pulp bound with CMC binder. An example of each of these header options is shown in the picture. Again, whatever header is chosen, care must be taken to avoid asymmetries, or your stingers will wobble all over the sky. |- | valign="top"|http://www.pyroguide.com/index.php?title=Image:Stinge07.jpg http://www.pyroguide.com/index.php?title=Image:Stinge07.jpgClick for larger imageNow a fuse is added to the side vent hole. A 1/8 inch drill bit (1/64th smaller than the one used to drill the hole in the tube to start with) is inserted into the hole and twisted gently by hand to open a small cavity in the black powder fuel grain. A glob of Meal D wetted with nitrocellulose lacquer is placed on the end of a 3-inch length of visco fuse. The globbed end is inserted into the vent hole as far as it will go. The lacquer will dry shortly and secure the fuse in place. I don't bother to bend it against the tube wall and affix it with tape, as recommended by Klofkorn. This practice has damaged the somewhat brittle visco and has caused failure of ignition on some of my stingers. If you use a more flexible fuse, this may still be a good idea to make the fuse more secure during storage and transport. |- | valign="top"|http://www.pyroguide.com/index.php?title=Image:Stinge08.jpg http://www.pyroguide.com/index.php?title=Image:Stinge08.jpgClick for larger imageA little bit of added stability at lift off can be achieved by gluing a custom reinforcement to the business end of the stinger. This is accomplished by tracing a circle around a stinger tube on a piece of strong tissue paper. A notebook paper hole reinforcement is then glued to the center of the circle. The circle is cut out and glued to the nozzle end of the stinger as shown in the picture. The launch spindle will be inserted through the hole of the reinforcement at launch time. The reinforcement helps the stinger spin about its central axis without wobbling. Another possibility I have seen used for this purpose is a standard paper end plug with a hole punched in it. The end plug is not glued into place so it will easily be blown out when the stinger flies. These end plugs may usually be re-used a few times before they become too badly charred. |- | valign="top"|http://www.pyroguide.com/index.php?title=Image:Stinge09.jpg http://www.pyroguide.com/index.php?title=Image:Stinge09.jpgClick for larger imageThe stinger missile requires a custom launch pin to support it prior to launch and during initial spin-up of the device. This can be as simple as a nail driven through a good sized piece of wood to give it a solid footing during launch. The last thing you want when these things start spinning is for the launch stand to tip over and send an angry stinger missile into your terrified audience. The nail is rounded at the end by a file to provide a good pivot point at the top of your stinger core. This picture shows a typical launch stand with two launch pins, one supporting a finished missile ready for launch. A little decorative paper has been added to give it a festive flair. All that remains is to light the fuse, retire to a safe distance and feel the rush these marvelous little rockets give to their creator and his audience. |}